2. Quality Assurance
• Quality assurance defines the objectives
of the project and reviews the overall
activities so that errors are corrected early
in the development process.
• Steps are taken in each phase to ensure
that there are no errors in the final
software
3. Quality assurance goals
• The software life cycle includes various
stages of development and each stage
has the goal of quality assurance.
4. Quality Factor specifications
• The goal of this stage is to define the
factors that contribute to the quality of the
candidate system.
• Factors determine the quality of a system:
– Correctness :the extent to which a program
meets system specifications and user
objectives
– Reliability: the degree to which the system
performs its intended functions over a time
5. Factors determine the quality of a system
• Efficiency: the amount of computer resources required by a program
to perform a function
• Usability: The effort required to learn and operate a system
• Maintainability: the ease with which program errors are located and
corrected
• Testability: the effort required to test a program to ensure its correct
performance
• Portability: the ease of transporting a program from one hardware
configuration to another.
• Accuracy: the required precision in input editing ,computations and
output
• Error Tolerance: error detection and correction versus error
avoidance
• Expandibility: Ease of adding or expanding the existing data base
• Access Control and Audit: control of access to the system and the
extent to which that access can be audited
• Communicativeness : how descriptive or useful the inputs and the
outputs of the system are
6. Software Requirement Specifications
• The quality assurance goal of this stage is to
generate the requirements document that
provides the technical specifications for the
design and the development of the software
• This document enhances the system’s quality by
formalizing communication between the system
developer and the user and provides the proper
information for accurate documentation
7. Software Testing and Implementation
• The quality assurance goal of the testing
phase is to ensure that completeness and
accuracy of the system and minimize the
retesting process .
• In the implementation phase, the goal is to
provide a logical order for the creation of
the modules and, in turn the creation of
the system.
